Development of a Dynamics-Based Continuous Time Motion Planning Algorithm for a 6 Degrees of Freedom Robot arm under constraints

Author(s):  
Keisuke UTO ◽  
Gaku TAKANO ◽  
Makoto OBAYASHI
Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1327-1335 ◽  
Author(s):  
Nir Shvalb ◽  
Boaz Ben Moshe ◽  
Oded Medina

SUMMARYWe introduce a novel probabilistic algorithm (CPRM) for real-time motion planning in the configuration space${\EuScript C}$. Our algorithm differs from a probabilistic road map (PRM) algorithm in the motion between a pair of anchoring points (local planner) which takes place on the boundary of the obstacle subspace${\EuScript O}$. We define a varying potential fieldfon ∂${\EuScript O}$as a Morse function and follow$\vec{\nabla} f$. We then exemplify our algorithm on a redundant worm climbing robot withndegrees of freedom and compare our algorithm running results with those of the PRM.


2016 ◽  
Vol 40 (3) ◽  
pp. 383-397 ◽  
Author(s):  
Bahman Nouri Rahmat Abadi ◽  
Sajjad Taghvaei ◽  
Ramin Vatankhah

In this paper, an optimal motion planning algorithm and dynamic modeling of a planar kinematically redundant manipulator are considered. Kinematics of the manipulator is studied, Jacobian matrix is obtained and the dynamic equations are derived using D’Alembert’s principle. Also, a novel actuation method is introduced and applied to the 3-PRPR planar redundant manipulator. In this approach, the velocity of actuators is determined in such a way to minimize the 2-norm of the velocity vector, subjected to the derived kinematic relations as constraints. Having the optimal motion planning, the motion is controlled via a feedback linearization controller. The motion of the manipulator is simulated and the effectiveness of the proposed actuation strategy and the designed controller is investigated.


2004 ◽  
Vol 16 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Kenji Kawashima ◽  
◽  
Takahiro Sasaki ◽  
Toshiyuki Miyata ◽  
Naohiro Nakamura ◽  
...  

After disasters, remote control of construction machinery is often required to ensure the safety of workers during excavation. However, only limited numbers of remote-controlled construction machinery exist, and they are typically larger than conventional machinery. After a disaster, the transportation of such machinery takes additional time and is often troublesome. Therefore, it would be desirable to develop a remote-control system that could easily be installed on ordinary construction machinery. A pneumatic humanoid robot arm is in the process of being developed. While considering the portability issue, a lightweight fiber knitted pneumatic artificial rubber muscle (PARM) was selected as the actuator for the arm. This arm can be installed on all construction machinery models, can be controlled remotely, and has been designed for easy installation and portability. In this research, construction machinery was retrofitted with a pneumatic robot that enables it to be operated remotely. This robot has 6 degrees of freedom and utilizes the fiber knitted PARM. Experiments were conducted to measure the static characteristics of the new PARM and to measure their performance in the remote control of construction machinery. Experimental results showed that the developed system is able to achieve handling two levers of machinery, one that controls back and forward movement and the other that controls the bucket. Experimental results showed that the developed system successfully operated construction machinery remotely.


2010 ◽  
Vol 2010.85 (0) ◽  
pp. _7-27_
Author(s):  
Nobutaka TSUJIUCHI ◽  
Takayuki KOIZUMI ◽  
Keita KITANO ◽  
Tohru HIROSHIMA ◽  
Yasunori ICHIKAWA ◽  
...  

Robotica ◽  
2007 ◽  
Vol 25 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Shuguo Wang ◽  
Jin Bao ◽  
Yili Fu

SUMMARYThis paper deals with sensor-based motion planning method for a robot arm manipulator operating among unknown obstacles of arbitrary shape. It can be applied to online collision avoidance with no prior knowledge of the obstacles. Infrared sensors are used to build a description of the robot's surroundings. This approach is based on the configuration space but the construction of the C-obstacle surface is avoided. The point automation is confined on some planes with square grids in the C-space. A path-searching algorithm based on square grids is used to guide the automation maneuvering around the C-obstacles on the selected planes. To avoid the construction of the C-obstacle surface, the robot geometry model is expanded, and the static collision detection method is used. Hence, the computation time is reduced and the algorithm can work in real time. The effectiveness of the proposed method is verified by a series of experiments.


2019 ◽  
Vol 31 (3) ◽  
pp. 493-499
Author(s):  
Thibault Barbié ◽  
◽  
Takaki Nishio ◽  
Takeshi Nishida

Conventional motion planners do not rely on previous experience when presented with a new problem. Trajectory prediction algorithms solve this problem using a pre-existing dataset at runtime. We propose instead using a conditional variational autoencoder (CVAE) to learn the distribution of the motion dataset and hence to generate trajectories for use as priors within the traditional motion planning approaches. We demonstrate, through simulations and by using an industrial robot arm with six degrees of freedom, that our trajectory prediction algorithm generates more collision-free trajectories compared to the linear initialization, and reduces the computation time of optimization-based planners.


Author(s):  
Celeste Colberg Poley ◽  
Balakumar Balachandran

Medical robots are increasingly being used to assist surgeons during procedures requiring precision. As reported in the literature, surgeons have been opting for minimally invasive surgery, as it reduces patient complications, overall patient recovery time, and hospital time for the patient. Robotic manipulators can be used to overcome natural limitations related to vision and human dexterity, and allow surgeons to transcend these limitations without having to sacrifice improvement in patient outcome. A desirable attribute of surgical robots is maneuverability similar to the human arm. The KUKA DLR Lightweight Robot Arm (LWR), with seven degrees of freedom, retains many of these human-like dexterity traits. Due to the KUKA robot arms maneuverability and flexibility, it is well-suited for intricate tasks based upon motion analyses and modeling of the compliance to path trajectory in addition to the overall smoothness of the path. This robot may be further programmed to be effective and precise for surgical applications. In the studies reported here, a unique Rapidly exploring Randomized Tree (RRT) based path-planning algorithm is developed and this algorithm is used to generate path plans between an initial state and a goal state for simulated models of robotic manipulator arms. Along with constraints, the RRT algorithm has been implemented to find paths for the chosen kinematic or dynamic robotic manipulator arm. Similar techniques are to be used to analyze the KUKA LWR IV+ system. Motion analyses have been carried out with consideration of motion trajectories and all possible locations of the end effector with unique constraints applied to the system. In these simulations, the Denavit-Hartenberg parameters were recorded, with special attention to movement restrictions. The results of the RRT paths generation, analysis of the manipulator arm trajectories, and simulations allow one to better determine the location of the end-effector at any given point in time and location. From this foundation, the generation of path-planning restrictions for the KUKA robots path programming is expected to take into account surgically restricted dangerous or undesirable zones. In future work, the trajectories of the KUKA robot and other manipulator arms are to be compared with the data available in the literature. This work holds promising implications for the improved use of such robot systems in surgical applications. For example, precise pre-programmed robotic movements are expected to be particularly helpful for surgeries in tight, anatomically restricted sites, with adjacent delicate tissues. Ultimately, it is expected that this type of novel robotic application will greatly aid surgeons in improving the precision and safety of surgical procedures, by reducing potential complications and minimizing potential nicks and tears, and working towards giving the surgeons the same ease that they have with traditional surgery.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Kevin Yu ◽  
Thomas Wegele ◽  
Daniel Ostler ◽  
Dirk Wilhelm ◽  
Hubertus Feußner

AbstractTelemedicine has become a valuable asset in emergency responses for assisting paramedics in decision making and first contact treatment. Paramedics in unfamiliar environments or time-critical situations often encounter complications for which they require external advice. Modern ambulance vehicles are equipped with microphones, cameras, and vital sensors, which allow experts to remotely join the local team. However, the visual channels are rarely used since the statically installed cameras only allow broad views at the patient. They neither allow a close-up view nor a dynamic viewpoint controlled by the remote expert. In this paper, we present EyeRobot, a concept which enables dynamic viewpoints for telepresence using the intuitive control of the user’s head motion. In particular, EyeRobot utilizes the 6 degrees of freedom pose estimation capabilities of modern head-mounted displays and applies them in real-time to the pose of a robot arm. A stereo-camera, installed on the end-effector of the robot arm, serves as the eyes of the remote expert at the local site. We put forward an implementation of EyeRobot and present the results of our pilot study which indicates its intuitive control.


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